That might sound a strange question but what it means is; should the galley on a conventional bridgedeck catamaran be up on the bridgedeck in the saloon, or down in a hull?

As I have said elsewhere, the majority of productions catamarans built these days are for the charter market. Charter catamarans are "floatels" and are not really lived on. Most charterers eat out as much as they can, just as hotel guests do. So a small galley is sufficient for the breakfast and snacks charterers cook.

Liveaboard and coastal cruisers, on the other hand, will need more worktop space and a lot more stowage room. They are probably going to cook underway, so being able to brace oneself is also important. Thus a corridor style galley (ie one in the hull) is ergonomic and also an efficient use of space.

If you do fit the galley on the bridgedeck then what do you put in the hulls? On a charter boat a pair of back-to-back shower compartments makes sense, but on a liveaboard boat they aren't necessary, so this part of the hull tends to become an unusable space. Meanwhile the saloon seating area is much smaller than it otherwise would be.

There is another problem as well. You have to move around the boat, so passageways have to be left clear to get down into the hulls, get to the seating areas or chart table, never mind work in the galley. All of which is wasted space.

So unless the boat is large (say over 45ft) I do not recommend a "Galley Up" design for any application. It's all another reason why you shouldn't chose a charter boat as a live aboard cruiser.

The Youtube clip below, taken from the Multihull sailors Have More Fun! video, shows first the galley of a Sagitta and then the saloon. Notice the lack of fiddles and gimbals, and then look at all the guys eating and looking out of the windows (try that on the average monohull!) while the cook steers.

Note: The "cuddy" catamarans, ie Wizard, Sango, Gypsy, Saturn, Romany etc do have galleys in the cuddy and they work very well there. (I have lived on and cruised extensively on both a Gypsy and Romany and also done a lot of coastal sailing in a Wizard and some in a Saturn)

https://www.youtube.com/watch?v=po0bS1R7_vM&list=PLT7PbPvOm8lzsFDoSIUv_Fumvr_Zquicc&index=45&t=0s